In the installation of tongue and groove hardwood plank flooring materials, pneumatic staplers are commonly used to drive staples used to adhere the planks to the floor. These staplers are designed to sit flat on top of the hardwood plank and locate against a tongued side of the plank such that they can precisely drive the staple at a 45° angle at a point just above the tongue. The driving angle of 45° and driving elevation at the point just above the tongue are fixed and standard for most all modern pneumatic hardwood staplers. The standard angle and point of entry for driving staples works well because the hardwood planks themselves normally have standard tongue and groove dimensions.
FIG. 14 shows the shape of a typical modern hardwood staple 50. As used herein, a typical hardwood staple 50 has dimensions defined as follows: dimension 51 is the length of the hardwood staple (sometimes also referred to as a “leg”), dimension 52 is the width of the hardwood staple (sometimes also referred to as a “crown”), and dimension 53 is the thickness of the hardwood staple. Modern hardwood staples are typically wire form products made from round wire. Hence the crown 52 of this kind of staple tends to form a longitudinally rounded surface 54. In comparison to other staples, modern hardwood flooring staples have long, brittle legs that will easily break if they are not supported during the driving process.
FIG. 10 illustrates by way of a cross sectional view the proper stapling of a tongue and groove hardwood plank. A first plank 11 has a hardwood staple 12 driven fully at a 45° angle into the vertex 13 of the exterior angle formed by an outer edge 14 and a tongue 15 of first plank 11. Hardwood staple 12 anchors first plank 11 to subfloor 16. Provided hardwood staple 12 is fully driven into the vertex 13, the tongue 15 of plank 11 fits easily into groove 18 of second plank 17, and the stapling process continues by stapling at same area of the next plank (the vertex 19 of second plank 17).
As shown in FIG. 12, the exterior angle formed by tongue outer edge 74 on the tongued side of the plank and a tongue 75 of a typical hardwood plank 71 may not be a 90° angle. The angle D formed between tongue outer edge 74 and tongue 75 is normally about 89.5°. Similarly, groove outer edge 70 on the opposite groove side of the plank is at an angle E of about 88.5° in relation to a centerline 77 of the hardwood plank. As shown in FIG. 13, these angles relieve tongue outer edge 74 and groove outer edge 70 from each other when they are butted together. This ensures tongue outer edge 74 and groove outer edge 70 will only contact near tongue top edge 72, and groove top edge 73. This ensures that there will be minimal interference between the edges which could create a gap at top of the joint.
When using pneumatic hardwood staplers, knots in the hardwood plank or drops in air pressure may cause the nailer to only partially drive the staple, leaving an undesirable exposed staple head. FIG. 11 illustrates the problem. Hardwood staple 1 has been partially driven into the side of the hardwood plank, leaving an exposed staple head 10. Whenever there is an exposed staple head, the tongue of a first plank and the groove of the next plank will not fit together. The floor installation process comes to a halt.
Presently, hardwood installers normally carry snips and conventional nail sets to hammer down partially driven staples. The staple legs have to be separated from the crown, and then the legs can be driven using a conventional nail set. This is a difficult, time consuming process. If a set tool were available to drive the entire exposed staple head the rest of the way into the side of the plank, it would greatly speed the process of installation. The process of driving a partially driven staple or exposed staple head will be referred to herein as a process of “finish hammering” the hardwood staple.
Tools have been developed for hammering nails into the side of tongue and grooved flooring materials, but none for finish hammering modern hardwood staples from pneumatic staplers. For example, U.S. Pat. No. 1,016,383 to Wellman discloses a set tool with a plate which sits flat on the hardwood plank. The plate includes a “V-rib” or approximately 90° internal angled surface formed in its base. The V-rib is shaped to conform to the plank at the external angle formed by the outer edge of the plank and the tongue of the plank (also referred to as a “rabbet” as this term is used in woodworking). Thus, the V-rib functions to position the plate at a precise location “to permit the effective drive of nails”. A circular “passage” for inserting a round headed nail is formed at a 45° degree angle through the plate to the vertex of the V-rib. Thus, when the point of the nail is inserted into the passage, it is automatically located at the optimal location for driving the nail at a 45° angle into the side of the plank.
In addition, the disclosed device includes a “punch or driving element” for use in connection with the plate. The punch is a generally cylindrical rod with a reduced outside diameter on one end which can slidably fit within the passage in the plate. This reduced diameter end can slide within the passage all the way to the bottom of the passage, and can thus drive the nail all the way down to the bottom of the passage. Thus, as this disclosure states, “the nail can be entirely driven into the flooring without removing the improved implement” (i.e., the “plate”).
Wellman's floor set may have worked well for the purpose of driving nails, but it is not suitable for the purpose of finish-hammering partially driven modern hardwood staples. The reason is that the passages are merely cylindrical holes designed for the passage of round headed nails. In comparison, modern hardwood staples are fairly thin, U-shaped metal wire implements. Effectively driving such staples requires that the staple be precisely supported all the way into the plank by means of a precision staple channel shaped to create a precision slide fit with the dimensions of the staple. If a user attempted to drive such a staple with only a hammer, and a blunt round ended punch running inside a passage such as Wellman's, the lack of support means would cause the thin metal legs of the staple to bend over or break. The passage of the Wellman device will not provide the necessary precision support means. Finally, the passages of this device are enshrouded due to the bulk of the body. A thinner body such as a tube having relieved edges would make the process of inserting an exposed staple head into a passage or staple slot much more easy to see.
U.S. Pat. No. 913,014 to Kafer discloses a staple set for hammering a heavy duty staple used to adhere fence wires to wooden fence posts. Kafer states the tubular body of his set tool can be made from scrap tube from “recycled pipe sections” or “boiler flues”. From this description, it may be inferred that such tubes are cylindrical shapes without internal features, and such is confirmed by his drawings. Kafer's tubes are threaded on both ends. One end receives a threaded cap having a staple slot. Since the staple slot of this device is formed only in the cap, the cross section of this slot is very thin. On the opposite end of the tube, a rod is inserted having a weighted handle. In use, the user inserts the fencing staple in the staple slot, grasps the weighted handle, and forcibly slides the rod to the bottom of the tube. The rod contacts and drives the staple into a post, thereby fastening a wire. This device is not useful for the purpose of finish hammering partially driven modern hardwood staples. The staple slot, being formed only in the cap of this device, is simply not long enough to support the long legs of these staples. Without precision support for both legs, the legs would bend or break. Furthermore, the end of the tubular body where the staple exits the device, and the driving head of the rod of this device, both have bulky square cross sections. Neither end surface has the type of relieved edges necessary to enter the external angle formed by the outer edge of the plank, and the tongue of the plank. Lastly, the staple driving head of the rod of this device appears to have no means for accepting the rounded crown of the staple, but appears only to be a flat surface. To finish hammer modern hardwood staples, it would be preferable to provide a staple receiving groove in the driving head of the rod. This is because that the crown of a modern hardwood staple has a rounded surface along the longitudinal axis of the crown. Such a groove would prevent the staple from bending, and would assist the user in locating the set tool over the head of the staple. Furthermore, it would be preferred that the tip of a set tool for finishing modern hardwood staples be as thin as possible, possibly made from a thin strip of metal. Such a thin tip could finish hammer the hardwood staple below flush into the side of the hardwood plank, making it easier to fit the tongue and grooved sections of the plank together. However, if a thin tip is employed, a precision groove on the driving end would become even more important in order to prevent such a tip from skipping over the crown of staple.
Other prior art set tools have been developed for driving staples, but they all have drawbacks. U.S. Pat. No. 1,213,334 to Chapman discloses a single-piece driving rod type staple set with a plurality of “sockets” (i.e., “blind-hole” staple channels) of varying depths formed in its driving head. The reference states that “the sockets are made of gradually decreasing depths so as to accommodate the staple at various stages of its entrance into the wood in which it is being set.” Thus, the user begins by inserting a staple in the deepest channel, and hammers on the opposite end to start the driving process. Once the driving head contacts the wood, the user inserts the staple head into one the shallower sockets, and the staple can be driven further. The legs of the staple are supported by the various sockets, preventing them from spreading or bending over. This device is not suitable for the purpose of finish hammering hardwood staples because the plurality of sockets requires a wide head. Such a wide head does not easily enter the external angle formed by the outside edge of the plank and the tongue of the plank. Furthermore, modern hardwood staples are by comparison much longer and thinner than the staples shown by Chapman. More sockets of even greater depth would be necessary, and the sockets would need to be narrow. Forming enough narrow blind sockets into the head would become impractical. What is needed is a tool with a single staple slot with a length at least as long as the hardwood staple, and a separate movable means of driving the head of the hardwood staple down the length of the staple channel.
Other similar set tools such as that disclosed in U.S. Pat. No. D493,079 S to Fowler, have more compact, relieved driving heads which include a single staple socket. Such a compact driving head can more easily enter the external angle formed by the outside edge of the plank, and the tongue of the plank. However, there is no means of support for the legs of the staple. This type of tool is not helpful in cases where the staple protrudes a significant distance from the hardwood plank. Without support during the driving process, the staple would simply bends over or breaks.
U.S. Pat. No. 2,430,532 to Rayburn discloses a spring activated set tool for small pins or brads used in soft woods. Specifically it is designed to function “without the use of a hammer”. This tool has a bottom body called a “guide” having a bore forming guidance means for pins or brads. The guide has relieved edges on the end where the opening of the bore is formed. The bore itself is a circular hole suitable to support round headed pins or brads. Additionally, the tool has a “head” with a hollow “barrel” that fits in a telescoping fashion over the guide. Within the barrel, a cylindrical plunger is mounted that inserts into the bore of the guide. A spring is inserted over the plunger and inside the barrel that rests on the top of the guide. In use, the user pushes the head, forcing the plunger to drive a pin or brad down the bore of the guide. Afterwards, the spring lifts the head and the plunger in the bore is raised. This makes space in the bore for insertion of another brad. Fast reloading of brads appears to be the primary benefit of the spring activation of this set tool.
Rayburn's set tool is not useful for finish hammering partially driven hardwood staples primarily because its round bore is not the right shape. Instead of a circular bore, a precision rectangular shaped staple slot sized for slide fit insertion of the crown of a hardwood staple is necessary. Furthermore, considerably more force is needed to finish hammer a hardwood staple, preferably by impact by a hammer. If a hammer were to be used, it would be preferable that the entire driving apparatus be more solid, and that it be closely supported along its entire length within a tubular body. Rayburn's plunger would likely bend within the open barrel if the forces necessary to drive a modern hardwood staple were repeatedly applied.
Finally, the process of finish hammering itself would be better facilitated by a spring urging the driving end of the rod (Rayburn's plunger) against the exposed head of the hardwood staple, rather than separating the hammering head (Rayburn's head and plunger) from the work (staple crown). This is because the finish hammering process likely requires repeated blows. A spring urging the driving head of the rod against the exposed head of the hardwood staple as it progresses down the staple channel would ensure the driving head was always in an ideal location. This could improve the precision and efficiency of the finish hammering operation.
What is needed is a set tool for finish hammering modern hardwood staples with a staple slot that properly supports the legs of these staples throughout the process. The body and the driving rod must have relieved edges so they can enter the external angle formed by the outer edge of the plank, and the tongue of the plank. The driving head of the rod needs a staple receiving groove to help locate the set tool on top of the exposed staple head, and to support the staple head as it is being finish hammered. A spring is needed to urge the staple receiving groove against the top of the exposed staple head at all times it is within the staple slot.